Power lift mechanism for plows



' June 18, 1929. o. A. K. PRINTZ 1,718,002

POWER LIFT MECHANISM FOR PLOWS Filed Aug. 26, 1927 2 Sheets-Sheet l June18, 1929. I o. A. K. PRINTZ POWER LIFT MECHANISM FOR FLOWS Filed Aug;26, 192'! 2 Sheets-Sheet 2 (Z U5 x J. V

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[I l 5 I Z5 J 2- fix r l/ GAAwr/QG Patented June 18, 1929.

UNITED STATES PATENT ()FFICE.

POWER LIFT MECHANISM FOR FLOWS.

Application filed August 26, 1927, Serial No. 215,717, and in SwedenSeptember 21, 1926.

This invention relates to improvements in power lift. mechanism for theframes of wheeled plows, of that type in which the plow frame is raisedby power derived from a carrying wheel by means of a lifting arm pivotedat its one end to the plow frame and at its other end to a lifting diskwhich may be clutched to said carrying wheel to rotate therewithsubstantially to the extent of half a revolution and which, when thusrotated causes said arm to effect the lifting of the frame.

The invention has for its object to provide a simple and reliable powerlift mechanism of the said type which is resistive to wear and easy tocontrol.

' In the accompanying drawings,-

Figure 1 is a View partly in elevation and partly in sectionillustrating a plow according to this invention in working position withthe lifting mechanism ready to commence a lifting operation.

Figure 2 is a view of the plow in elevated position.

Fig. 3 is a top-plan view of the lifting mechanism partly in sectionalong the line 33 of Fig. 2;

Fig. 4 is a side elevation of the fork-shaped clutch lever of thelifting mechanism;

Fig. 5 is a top plan view of said lever;

Fig. 6 is a top plan View and Fig. 7 is an end view of the control leverarm.

It is to be noted that only those parts of the plow necessary for theunderstanding of the invention have been illustrated in the drawings.

In the drawings, the numeral 1 indicates the plow frame comprisingsuitably braced beams carrying the plow bases (not shown) at theirdownwardly bent ends. 2 indicates a bearing bracket secured to the framefor the accommodation of one carrying wheel crank axle 3 as well as ofthe straight lifting arm 4, the latter having its lower end pivoted tothe lifting disk 5 at 6. Secured to the beams are, furthermore, twobearings for the accommodation of the other carrying wheel crank axle,though this is not shown in the drawing. The lifting disk 5 is mountedloosely on the spindle portion 7 of the crank axle 3, and looselymounted on said spindle portion is also the carrying wheel 8. The hub ofsaid wheel 8 is provided at its inner end with a hollow cylindricalportion 15 the lever 13 carries the roller 11 to engage the recesses 10of the carrying wheel hub and, at 17, Fig. 4, a pivotally mounted boltor rod 18 loosely engaging at its other end into a bracket 19 secured to.the lifting disk. Surrounding said bolt orsrod is a spring 20 tendingto retain the lever 13 in either of two extreme positions correspondingto the disengaged and engaged state, respectively, of the lifting disk 5relatively to the carrying wheel 8.

On the inner side of the wall 15 one end 21 of the lever 13 is shaped asa cam surface adapted to be operated by a roller 23 carried by thecontrol lever 22 in order to cause the clutching of the roller lever 13and thus also of the lifting disk 5 to the carrying wheel 8, whereas theother end 24 of the lever 13 is adapted in the lifting throw of thelifting disk to abut against a lug 25 on a housing 26 rigidly secured tothe carrying wheel axle 3 to thereby effect the unclutching of thelifting disk from the carrying wheel. In order to limit the rotation ofthe lifting disk in its lifting throw a lug 27 is provided on the diskadapted to abut against the lug 25 on the housing 26. The lifting disk 5is, furthermore, provided with a lug 28' adapted in the elevatedposition of the plow to be in close proximity to a roller 29 looselymounted on an arm 30 pivoted to the side wall of the housing 26 whichforms an extension of the control lever 22. The axes of the rollers 29and 23 coincide the roller 23 being carried by an arm 31 which ispivoted at 32 to the arm 30. The roller 23 is situated in the path ofthe end 21 of lever 13 and may engage said end for the clutching of thelifting mechanism, whereas the roller 29 is situated to the side of saidpath but within reach of the lug 28 on which it acts to restore the plowto lowered position. A spring 33 inserted between the arms 30 and 31acts to normally maintain the arm 31 in engagement with a lug 34 on thearm 30 while permitting the arm 31 to turn to allow the end 21 of lever13 to pass, when the lifting disk is turned back in the lowering of theplow frame.

The operation is as follows:

When the plow frame is to be lifted, a pull is exerted on a rope 35attached to the control lever 22 in the direction indicated by the arrowin Figs. 1 and 2. The control lever 22 which is rigidly connected to thearm 30 within the housing 26 will thus cause said arm 30 and with itthearm 31 to turn until the roller 23 engagesthe end 21 of the lever 13 andturns same to cause the roller 11 to engage any of the recesses 10 inthe cylindrical hub portion 9 of the carrying wheel 8. Said carryingwheel will now rotate the lifting disk 5 thereby causing the journal 6of the lifting arm 4 to raise said arm and with it the plow frame 1.Towards the end of this movement the end 24 of the lever 13 will abutagainst the lug 25 of the housing 26 thereby causing the lever 13 in thecontinued rotation of the lifting disk to turn so as to disengage theroller 11 from the recess 10 with which it has been engaged therebyinterrupting the transmission of power to the lifting disk.Substantially simultaneously with said interruption the lug 27 of thelifting disk abuts against the lug 25 causing the lifting disk to stopin a position in which that end of the lifting arm 4: mounted onthejournal 6 has passed the upper dead center position to some extent. 7

When the plow shall again be lowered a pull is again exerted on the rope35 in the same direction as before whereby the arm 30 will be turneduntil the roller 29 engages the lug 28 and the lifting disk. A continuedpull on the rope causes the arm 30 to turn the lifting disk backwardlyuntil the journal 6 passes the upper dead center position allowing thelifting disk to restore to normal under the action of the plow framewhen dropping by gravity to its working position.

The mechanism for limiting the drop of the plow frame falls outside thescope of the present invention but may in well knownmanner comprise alug secured to the plow frame against which the carrying wheel axle 3may drop in its rotation and which lug may be adjusted according to thedepth of plowing desired.

What 1 claim is:

1. In a lifting mechanism for wheeled plows, the combination withaframe, of a crank axle mounted in said frame, a housing rigid with saidaxle, a carrying wheel loose on said axle, a recessed member rigid withsaid wheel, a lifting disk loose on said axle, an oscillatory liftingarm pivoted to said lifting disk and to said frame, of a lever pivotallymounted on said lifting disk, a roller on said lever to engage saidrecessed memher, a cam surface on said lever, and a control leverpivoted to said housing to act upon said cam surface to effect saidengagement.

2. In a lifting mechanism for wheeled plows, the combination with aframe, of a crank axle mounted in said frame,a housing rigid with saidcrank axle, a carrying wheel loose on said axle, a recessed member rigidwith said wheel, a lifting disk loose on said axle, an oscillatorylifting arm pivoted to said lifting disk and to said frame, afork-shaped lever pivotally mounted intermediate its ends on saidlifting disk, oneend of said lever being shaped as a cam surface, aroller on said lever to engage said recessed member, a control leverpivoted to said h0using, a roller on said control lever to act on saidcam surface to effect said engagement, and a lug on said housing to beengaged by the other end of said fork-shaped lever to release saidengagement. I

3. In a lifting mechanism for wheeled plows, the combination with aframe, of a crank axle mounted in said frame, a carrying wheel loose onsaid axle, a recessed member rigid with said wheel, a lifting disk looseon said axle, an oscillatory lifting arm pivoted to said lifting diskand to said frame, a housing rigid with "said axle, a control leverpivoted to said housing, a fork-shaped lever pivotally mountedintermediate its ends on said lifting disk, a roller on one end of saidlever to engage said recessed member, a rod pivoted to the other end ofsaid lever and engaging loosely said lifting disk, and a spring on saidrod to maintain the lever in either of two end positions correspondingto engaged and disengaged state of the lifting disk. v

In testimony whereof I have signed my name.

OSCAR ADOLF KRISTIAN PRINTZ.

